There is poor agreement between manual auscultatory and automated oscillometric methods for the measurement of blood pressure in normotensive pregnant women

Validation of the AViTA BPM636 upper arm blood pressure monitor in adults and pregnant women according to the ANSI/AAMI/ISO 81060-2:2013

OBJECTIVE

To evaluate the accuracy of the AViTA oscillometric upper arm home blood pressure (BP) monitor in adult and pregnant populations according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/ International Organization for Standardization (ANSI/AAMI/ISO) Universal Standard (ISO 81060-2:2013).

METHODS

BP measurements on the upper arm were performed on 85 adult subjects and 46 pregnant subjects. The AViTA BPM636 and a standard mercury reference sphygmomanometer were applied and followed the same arm sequential BP measurement method. The universal cuff of the test device was used for arm circumference of 22-42 cm.

RESULTS

For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings was 1.1 ± 5.49/2.9 ± 5.17 mmHg (systolic/diastolic) for adults; and -2.2 ± 5.93/1.5 ± 4.92 mmHg (systolic/diastolic) for pregnant women. For criterion 2, the SD of the averaged BP differences between the test device and reference BP per adult subject was 4.45/4.20 mmHg (systolic/diastolic) and per pregnant women was 4.66/3.96.

CONCLUSION

The AViTA BPM636 had passed the criteria of the ANSI/AAMI/ISO 81060-2:2013 protocol and can be recommended for home BP measurements in adults and pregnant populations.

Measurement of Blood Pressure in Humans: A Scientific Statement From the American Heart Association

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. This article provides an updated American Heart Association scientific statement on BP measurement in humans. In the office setting, many oscillometric devices have been validated that allow accurate BP measurement while reducing human errors associated with the auscultatory approach. Fully automated oscillometric devices capable of taking multiple readings even without an observer being present may provide a more accurate measurement of BP than auscultation. Studies have shown substantial differences in BP when measured outside versus in the office setting. Ambulatory BP monitoring is considered the reference standard for out-of-office BP assessment, with home BP monitoring being an alternative when ambulatory BP monitoring is not available or tolerated. Compared with their counterparts with sustained normotension (ie, nonhypertensive BP levels in and outside the office setting), it is unclear whether adults with white-coat hypertension (ie, hypertensive BP levels in the office but not outside the office) have increased cardiovascular disease risk, whereas those with masked hypertension (ie, hypertensive BP levels outside the office but not in the office) are at substantially increased risk. In addition, high nighttime BP on ambulatory BP monitoring is associated with increased cardiovascular disease risk. Both oscillometric and auscultatory methods are considered acceptable for measuring BP in children and adolescents. Regardless of the method used to measure BP, initial and ongoing training of technicians and healthcare providers and the use of validated and calibrated devices are critical for obtaining accurate BP measurements.

Accuracy of Blood Pressure Measurement Devices in Pregnancy: A Systematic Review of Validation Studies

The accurate measurement of blood pressure (BP) in pregnancy is essential to guide medical decision making that affects both mother and fetus. The aim of this systematic review was to determine the accuracy of ambulatory, home, and clinic BP measurement devices in pregnant women. We searched Ovid MEDLINE, The Cochrane Library, EMBASE, CINAHL EBSCO, ClinicalTrials.gov, International Clinical Trials Registry Platform, and dabl from inception through August 3, 2017 for articles that assessed the validity of an upper arm BP measurement device against a mercury sphygmomanometer in pregnant women. Two independent investigators determined eligibility, extracted data, and adjudicated protocol violations. From 1798 potential articles identified, 41, that assessed 28 devices, met the inclusion criteria. Most articles (n=32) followed a standard or modified American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization, British Hypertension Society, or European Society of Hypertension validation protocol. Several articles described the results of validation studies performed on >1 device (n=7) or in >1 population of pregnant women (n=12), comprising 64 pairwise validity assessments. The device was validated in 61% (32 of 52) of studies which used a standard or modified protocol. Only 34% (11 of 32) of the studies wherein the device was successfully validated were performed without a protocol violation. Given the implications of inaccurate BP measurement in pregnant women, healthcare providers should be aware of and try to use the BP measurement devices which have been properly validated in this population.

Estimate of nocturnal blood pressure and detection of non-dippers based on clinical or ambulatory monitoring in the inpatient setting

BACKGROUND

Ambulatory blood pressure monitoring is regarded as the gold standard for monitoring nocturnal blood pressure (NBP) and is usually performed out of office. Currently, a novel method for monitoring NBP is indispensible in the inpatient setting. The widely used manual BP monitoring procedure has the potential to monitor NBP in the hospital setting. The feasibility and accuracy of manual sphygmomanometer to monitor NBP has not been explored widely.

METHODS

A cross-sectional study was conducted at the cardiology department of a university-affiliated hospital to study patients with mild-to-moderate essential hypertension. One hundred and fifty-five patients were recruited to compare BP derived from a manual device and ambulatory BP monitoring (ABPM). The manual BP measurement was performed six times at 22:00, 02:00, 06:00, 10:00, 14:00 and 18:00 h. The measurements at 22:00, 02:00 and 06:00 h were defined as night-time and the others as daytime. ABPM was programmed to measure at 30-min intervals between measurements.

RESULTS

All-day, daytime and night-time BP did not differ significantly from 24-h ambulatory systolic BP [all-day mean difference -0.52±4.67 mmHg, 95% confidence interval (CI) -1.26 to 0.22, P=0.168; daytime mean difference 0.24±5.45 mmHg, 95% CI -0.62 to 1.11, P=0.580; night-time mean difference 0.30±7.22 mmHg, 95% CI -0.84 to 1.45, P=0.601) rather than diastolic BP. There was a strong correlation between clinical and ambulatory BP for both systolic and diastolic BP. On the basis of ABPM, 101 (65%) patients were classified as non-dippers, compared with 106 (68%) by manual sphygmomanometer (P<0.001).

CONCLUSIONS

Traditional manual sphygmomanometer provides similar daytime and night-time systolic BP measurements in hospital. Moreover, the detection of non-dippers by manual methods is in good agreement with 24-h ABPM. Further studies are required to confirm the clinical relevance of these findings by comparing the association of NBP in the hospital ward assessed by manual monitoring with preclinical organ damage and cardiovascular and cerebrovascular outcomes.

Invasive versus non-invasive monitoring of acute severe hypertension in women with pre-eclampsia

OBJECTIVE

To compare the accuracy of two non-invasive methods of blood-pressure measurement with intra-arterial measurement in women with pre-eclampsia and acute severe hypertension.

METHODS

This descriptive, cross-sectional study prospectively enrolled 23 women with pre-eclampsia and acute severe hypertension for continuous intra-arterial blood-pressure monitoring. Simultaneous monitoring was performed with a manual and an automated, non-invasive device during episodes of severe hypertension. The paired T-test was used to compare measured values. The accuracy of a MAP⩾125mmHg in detecting a systolic blood pressure⩾160mmHg was determined.

RESULTS

There was a weak correlation between intra-arterial and automated as well as intra-arterial and manual systolic values (r=0.34, p<0.01; r=0.41, p<0.00, respectively). Better correlation was found amongst diastolic values. The differences between the mean intra-arterial (94±11mmHg) and automated (96±12mmHg) diastolic values as well as intra-arterial and manual diastolic measurements (94±14mmHg) were not significant (p=0.20, 0.65, respectively). A mean arterial pressure⩾125mmHg was not accurate in detecting a systolic value⩾160mmHg, with low sensitivities (17.2-35.9%) and specificities (0-50%) for all three methods.

CONCLUSIONS

When compared to intra-arterial monitoring, the automated and manual methods showed weak correlation with systolic but better correlation with diastolic values. A mean arterial pressure⩾125mmHg was not accurate in detecting systolic peaks. When protection against cerebral haemorrhage is paramount, intra-arterial measurement of systolic values is best.

The context & clinical evidence for common nursing practices during labor

The purpose of this article is to review the context and current evidence for common nursing care practices during labor and birth. Although many nursing interventions during labor and birth are based on physician orders, there are a number of care processes that are mainly within the realm of nursing practice. In many cases, particularly in community hospitals, routine physician orders for intrapartum care provide wide latitude for nurses in how they ultimately carry out those orders. An important consideration of common nursing practices during labor is the context or practice model in which those practices occur. Nursing practice is not the same in all clinical environments. Intrapartum nursing practice consists of an assortment of different roles depending on the circumstances, hospital setting, and context in which it takes place. A variety of intrapartum nursing practice models have evolved as a result and in response to the range of sizes, locations, and provider practice styles found in hospitals providing obstetric services. A summary of intrapartum nursing models is presented. The evidence is reviewed for the three most common clinical practices for which nurses have primary responsibility in most settings and that comprise the majority of their time in caring for women during labor: (1) maternal-fetal assessment, (2) management of oxytocin infusions, and (3) second-stage care. Evidence exists for these nursing interventions that can be used to promote maternal-fetal well-being, minimize risk, and enhance patient safety.

Measuring blood pressure using the mercury sphygmomanometer

Automated blood pressure devices have been embraced by clinicians for their convenience and ease of use. However, the pressure to remove mercury-containing medical devices is leading to the demise of the mercury sphygmomanometer and the loss of manual blood pressure measurement skills. The article argues that there is still a place for the mercury sphygmomanometer, particularly when a clinical decision is based on the blood pressure readings. It presents a review of the available literature to explain the rationale for the use of manual sphygmomanometry and gives a step-by-step guide to the procedure with current supporting evidence. There is a brief discussion of special considerations when dealing with certain client groups. Normal blood pressure ranges for adults and children have been included along with a definition of hypertension for both groups.

Cross sectional study of automated blood pressure measurements throughout pregnancy

OBJECTIVE

To generate reliable new reference ranges for pregnancy blood pressure from a large population.

DESIGN

A prospective cross sectional study.

SETTING

Obstetric outpatient clinic, Zurich University Hospital.

SAMPLE

Accurately dateable singleton pregnancies (Caucasian: n= 3234; Asian [predominantly from Sri Lanka, Thailand and the Philippines]: n= 577; Black n= 212).

METHODS

Between January 1996 and February 2000 blood pressure was determined in 4023 pregnant women using an oscillometric automated device (Dinamap) according to British Hypertension Society recommendations. Women receiving antihypertensive medication were excluded.

MAIN OUTCOME MEASURE

Blood pressure.

RESULTS

Only the means of duplicate measures at the booking visit (5-42 weeks) were used in the analysis. Mean blood pressure decreased from early to mid pregnancy before increasing to levels 4 mmHg higher at term than in early pregnancy. Values >130/80 and <90/50 mmHg were above the 95th and below the 5th centiles, respectively. Parity, age and body mass index were significant determinants in Caucasians. Blood pressure was slightly lower in Asians and Blacks.

CONCLUSIONS

The current World Health Organisation definition of high diastolic blood pressure (>or=90 mmHg on two occasions) reflects values >2 standard deviations from the mean. This may be too conservative as threshold for detecting women at risk of pre-eclampsia. Further studies are required to determine the prognostic implications of gestational values >or=95th centile (>or=130/80 mmHg) and <or=5th centile (<or=90/50 mmHg).